Graphics card upgrade question for Mac Pro:

I have a Mac Pro, 2006 model, I think? I bought it in 2007. It is a 2x 2.66 dual core Intel Xeon. Right now it has an NVIDIA GeForce 7300 GT graphic card. I want to upgrade the Graphics Card. I mostly run photoshop for retouching and compositing, but often with very large files with many layers. This card just isn't cutting it anymore for CS5 and I've had a lot of problems with text, despite doing everything I can to maximize the performance according to Adobe troubleshooting. I don't know that much about graphics cards. What would you recommend for this model Mac Pro and photoshop? Money is a little tight right now, so price is a consideration, but I can spend what is needed to get good performance. I am a professional and I need good equipment.

I should add, that I am currently use an old 23" cinema ADC cinema display with an DVI to ADC adapter. I have a second monitor with the same configuration. I would love to be able to hook them both up at once, but I can do without if necessary.

- Too many "beachballs", read this: Beachballs- Computer seems slower than it used to? Read this for some slow computer tips: Speedup- Almost full hard drive? Some solutions. Out of Space- Apple Battery Info. Battery

The adapter may be a bottleneck. Had similar problems slow boot times, unable to boot from disc etc so purchased a BenQ 22" LED. Sadly the day of ADC is long gone.

For your needs can recommend the ATI Radeon HD4870 1GB card, which is a flashed PC card. Have a look on eBay for such. Can also recommend local338 dealer from Hong Kong purchased card, PCI equipment from them many times. Next choice would be a slower nVidia GeForce 8800GT which must be for 1st Generation Mac Pros. There are two versions.

Hang on to those original install discs like grim death! Using OS X.7 or later make a bootable USB thumb drive before running Installer!